The present invention relates generally to fabrication of orthotic devices, and more particularly to a method of producing orthotic devices utilizing an optimized milling path.
The prior art provides for the computer controlled manufacturing of orthotic devices or appliances from a workpiece of solid material, such as plastic. Typically, such a process begins with the generation of computer model of a patient's foot, for example. This may be accomplished by using an optical scanner or electro-mechanical contact apparatus. The computer model may be adapted with a prescriptive modification to generate computer model of a desired orthotic device. A milling tool may be used to selectively remove material from the plastic workpiece so as to expose a surface contour corresponding to the desired orthotic device computer model. Thus, the remaining material of the workpiece forms the basis of the desired orthotic device. This may be accomplished via a computer numerical controlled (CNC) process. Subsequent to such CNC process further machining may be required for final completion of the device. For example, a surface machining process may be desired, such as grinding, polishing or sandblasting.
For example, a prior art milling path is disclosed in U.S. Pat. No. 5,054,148 which as understood calls for the milling tool to translate in a back and forth motion across the desired orthotic device to form a series of parallel grooves. However, such a prior art milling path requires abrupt direction changes, 180 degree turns. Such abrupt direction changes require that the associated milling tool decelerate upon making such abrupt direction changes and may even result in a momentary stoppage of motion. Subsequently, the milling tool is required to quickly accelerate to continue milling. Such deceleration and acceleration cycling is inefficient in terms of overall fabrication time of the orthotic device.
It is therefore evident that there exists a need in the art for a method of more efficiently producing orthotic devices in comparison to the prior art.